Heated shaving razors

ABSTRACT

A shaving razor cartridge with a housing having a guard, a cap, and one or more blades located between the guard and the cap. The guard is positioned in front of the one or more blades and the cap is positioned behind said one or more blades. A heating element is mounted to the housing for transferring heat during a shaving stroke. The heating element includes a skin contacting surface and an opposing bottom surface defined by a perimeter wall. An insulating member is positioned within the perimeter wall. The insulating member has a first surface facing the bottom surface of the heating element and a second surface.

FIELD OF THE INVENTION

The present invention relates to shaving razors and more particularly toheated razors for wet shaving.

BACKGROUND OF THE INVENTION

Users of wet-shave razors generally appreciate a feeling of warmthagainst their skin during shaving. The warmth feels good, resulting in amore comfortable shaving experience. Various attempts have been made toprovide a warm feeling during shaving. For example, shaving creams havebeen formulated to react exothermically upon release from the shavingcanister, so that the shaving cream imparts warmth to the skin. Also,razor heads have been heated using hot air, heating elements, andlinearly scanned laser beams, with power being supplied by a powersource such as a battery. Razor blades within a razor cartridge havealso been heated. The drawback with heated blades is they have minimalsurface area in contact with the user's skin. This minimal skin contactarea provides a relatively inefficient mechanism for heating the user'sskin during shaving.

However the delivery of more to the skin generates safety concerns(e.g., burning or discomfort).

Accordingly, there is a need to provide a shaving razor capable ofdelivering safe and reliable heating that is noticeable to the consumerduring a shaving stroke.

SUMMARY OF THE INVENTION

The invention features, in general, a simple, efficient shaving razorsystem having a housing with a guard, a cap, and one or more bladeslocated between the guard and the cap. The guard is positioned in frontof the one or more blades, and the cap is positioned behind said one ormore blades. A heating element is mounted to the housing fortransferring heat during a shaving stroke. The heating element includesa skin contacting surface and an opposing bottom surface defined by aperimeter wall. An insulating member is positioned within the perimeterwall. The insulating member has a first surface facing the bottomsurface of the heating element and a second surface.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. It is understoodthat certain embodiments may combine elements or components of theinvention, which are disclosed in general, but not expressly exemplifiedor claimed in combination, unless otherwise stated herein. Otherfeatures and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter that is regarded as thepresent invention, it is believed that the invention will be more fullyunderstood from the following description taken in conjunction with theaccompanying drawings.

FIG. 1 is a perspective view of one possible embodiment of a shavingrazor system.

FIG. 2 is an assembly view of one possible embodiment of a heatingelement and insulating member that may be incorporated into the shavingrazor system of FIG. 1.

FIG. 3 is an assembly view of the shaving razor cartridge of FIG. 1.

FIG. 4 is a bottom view of the shaving cartridge of FIG. 3

FIG. 5 is a schematic view of an electrical circuit, which may beincorporated into the shaving razor system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, one possible embodiment of the present disclosureis shown illustrating a shaving razor system 10. In certain embodiments,the shaving razor system 10 may include a shaving razor cartridge 12mounted to a handle 14. The shaving razor cartridge 12 may be fixedly orpivotably mounted to the handle 14 depending on the overall desired costand performance. The handle 14 may hold a power source, such as one ormore batteries (not shown) that supply power to a heating element 16. Incertain embodiments, the heating element 16 may comprise a metal, suchas aluminum or steel.

The shaving razor cartridge 12 may be permanently attached or removablymounted from the handle 14, thus allowing the shaving razor cartridge 12to be replaced. The shaving razor cartridge 12 may have a housing 18with a guard 20, a cap 22 and one or more blades 24 mounted to thehousing 18 between the cap 22 and the guard 20. The guard 20 may betoward a front portion of the housing 18 and the cap 22 may be toward arear portion of the housing 18 (i.e., the guard 20 is in front of theblades 24 and the cap is behind the blades 24). The guard 20 and the cap22 may define a shaving plane that is tangent to the guard 20 and thecap 22. The guard 20 may be a solid or segmented bar that extendsgenerally parallel to the blades 24. In certain embodiments, the heatingelement 16 may be positioned in front of the guard 20. The heatingelement 16 may comprise a skin contacting surface 30 that delivers heatto a consumer's skin during a shaving stroke for an improved shavingexperience. The heating element may be mounted to either the shavingrazor cartridge 12 or to a portion of the handle 14.

In certain embodiments, the guard 20 may comprise a skin-engaging member26 (e.g., a plurality of fins) in front of the blades 24 for stretchingthe skin during a shaving stroke. In certain embodiments, theskin-engaging member 24 may be insert injection molded or co-injectionmolded to the housing 18. However, other known assembly methods may alsobe used such as adhesives, ultrasonic welding, or mechanical fasteners.The skin engaging member 26 may be molded from a softer material (i.e.,lower durometer hardness) than the housing 18. For example, the skinengaging member 26 may have a Shore A hardness of about 20, 30, or 40 toabout 50, 60, or 70. The skin engaging member 26 may be made fromthermoplastic elastomers (TPEs) or rubbers; examples may include, butare not limited to silicones, natural rubber, butyl rubber, nitrilerubber, styrene butadiene rubber, styrene butadiene styrene (SBS) TPEs,styrene ethylene butadiene styrene (SEBS) TPEs (e.g., Kraton), polyesterTPEs (e.g., Hytrel), polyamide TPEs (Pebax), polyurethane TPEs,polyolefin based TPEs, and blends of any of these TPEs (e.g.,polyester/SEBS blend). In certain embodiments, skin engaging member 26may comprise Kraiburg HTC 1028/96, HTC 8802/37, HTC 8802/34, or HTC8802/11 (KRAIBURG TPE GmbH & Co. KG of Waldkraiburg, Germany). A softermaterial may enhance skin stretching, as well as provide a more pleasanttactile feel against the skin of the user during shaving. A softermaterial may also aid in masking the less pleasant feel of the hardermaterial of the housing 18 and/or the fins against the skin of the userduring shaving.

In certain embodiments, the blades 24 may be mounted to the housing 18and secured by one or more clips 28 a and 28 b. Other assembly methodsknown to those skilled in the art may also be used to secure and/ormount the blades 24 to the housing 18 including, but not limited to,wire wrapping, cold forming, hot staking, insert molding, ultrasonicwelding, and adhesives. The clips 28 a and 28 b may comprise a metal,such as aluminum for conducting heat and acting as a sacrificial anodeto help prevent corrosion of the blades 24. Although five blades 24 areshown, the housing 18 may have more or fewer blades depending on thedesired performance and cost of the shaving razor cartridge 12.

In certain embodiments, it may be desirable to provide heat in front ofthe blades 24. For example, the heating element 16 may be positioned infront of the guard 20 and/or the skin engaging member 26. The heatingelement 16 may have a skin contacting surface 30 for delivering heat tothe skin's surface during a shaving stroke. As will be described ingreater detail below, the heating element 16 may be mounted to thehousing 18 and in communication with the power source (not shown). Theheating element 16 may be connected to the power source with a flexiblecircuit 32.

The cap 22 may be a separate molded (e.g., a shaving aid filledreservoir) or extruded component (e.g., an extruded lubrication strip)that is mounted to the housing 18. In certain embodiments, the cap 22may be a plastic or metal bar to support the skin and define the shavingplane. The cap 22 may be molded or extruded from the same material asthe housing 18 or may be molded or extruded from a more lubriciousshaving aid composite that has one or more water-leachable shaving aidmaterials to provide increased comfort during shaving. The shaving aidcomposite may comprise a water-insoluble polymer and a skin-lubricatingwater-soluble polymer. Suitable water-insoluble polymers which may beused include, but are not limited to, polyethylene, polypropylene,polystyrene, butadiene-styrene copolymer (e.g., medium and high impactpolystyrene), polyacetal, acrylonitrile-butadiene-styrene copolymer,ethylene vinyl acetate copolymer and blends such aspolypropylene/polystyrene blend, may have a high impact polystyrene(i.e., Polystyrene-butadiene), such as Mobil 4324 (Mobil Corporation).

Suitable skin lubricating water-soluble polymers may includepolyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, hydroxypropylcellulose, polyvinyl imidazoline, and polyhydroxyethylmethacrylate.Other water-soluble polymers may include the polyethylene oxidesgenerally known as POLYOX (available from Union Carbide Corporation) orALKOX (available from Meisei Chemical Works, Kyota, Japan). Thesepolyethylene oxides may have molecular weights of about 100,000 to 6million, for example, about 300,000 to 5 million. The polyethylene oxidemay comprise a blend of about 40 to 80% of polyethylene oxide having anaverage molecular weight of about 5 million (e.g., POLYOX COAGULANT) andabout 60 to 20% of polyethylene oxide having an average molecular weightof about 300,000 (e.g., POLYOX WSR-N-750). The polyethylene oxide blendmay also contain up to about 10% by weight of a low molecular weight(i.e., MW<10,000) polyethylene glycol such as PEG-100.

The shaving aid composite may also optionally include an inclusioncomplex of a skin-soothing agent with a cylcodextrin, low molecularweight water-soluble release enhancing agents such as polyethyleneglycol (e.g., 1-10% by weight), water-swellable release enhancing agentssuch as cross-linked polyacrylics (e.g., 2-7% by weight), colorants,antioxidants, preservatives, microbicidal agents, beard softeners,astringents, depilatories, medicinal agents, conditioning agents,moisturizers, cooling agents, etc.

Referring to FIG. 2, one possible embodiment of a heating element isshown that may be incorporated into the shaving razor system of FIG. 1.The heating element 16 may have a bottom surface 34 opposing the skincontacting surface 30. A perimeter wall 36 may define the bottom surface34. The perimeter wall 36 may have one or more legs 38 extending fromthe perimeter wall 36, transverse to and away from the bottom surface34. For example, FIG. 2 illustrates four legs 38 extending from theperimeter wall 36. As will be explained in greater detail below, thelegs 38 may facilitate locating and securing the heating element 16during the assembly process. An insulating member 40 may be positionedwithin the perimeter wall 36. In certain embodiments, the insulatingmember 40 may comprise a ceramic or other materials having high thermalconductivity and/or excellent electrical insulator properties. Theinsulating member 40 may have first surface 42 (see FIG. 3) that facesthe bottom surface 34 of the heating element and a second surface 44opposite the first surface 42. The perimeter wall 36 may help containand locate the insulating member 40. In certain embodiments, theinsulating member 40 may be secured to the bottom surface 34 by variousbonding techniques generally known to those skilled in the art. It isunderstood that the perimeter wall 36 may be continuous or segmented(e.g., a plurality of legs or castellations).

The second surface 44 of the insulating member 40 may comprise aconductive heating track 46 that extends around a perimeter of theinsulating member 40. An electrical circuit track 48 may also extendaround a perimeter of the second surface 44. In certain embodiments, theelectrical circuit track 48 may be positioned within the heating track46. The electrical circuit track 48 may be spaced apart from the heatingtrack 46. The electrical circuit track 48 may comprise a pair of thermalsensors 50 and 52 that are positioned on opposite lateral ends (e.g., onleft and right sides) of the second surface 44 of the insulating member40. In certain embodiments, the thermal sensors 50 and 52 may beNTC-type thermal sensors (negative temperature coefficient).

The positioning of the thermal sensors 50 and 52 opposite lateral endsof the second surface 44 of the insulating member 40 may provide for asafer and more reliable measurement of the temperature of the heatingelement 16 (e.g., the bottom surface 34) and/or the insulating member40. For example, if only one end of the heating element is exposed tocool water (e.g., when the shaving razor cartridge is being rinsed inbetween shaving strokes), that end of the heating element will be coolerthan the other end of the heating element. Lateral heat flow from oneend to the opposite of heating elements are typically poor. Temperatureequalization is very slow and limited by the heat resistance of themechanical heater system. Accordingly, a single sensor or multiplesensor(s) that take an average temperature will not provide an accuratereading and may over heat the heating element, which may lead to burningof the skin. Power to the heating element 16 may never turn off becauseof the unbalanced temperature of the heating element 16 (i.e., theaverage temperature or the individual temperature of the single sensorexposed to the cool water may never be reached). Accordingly, thethermal sensors 50, 52 may independently output a signal related to thetemperature of the heating element 16 to the temperature controlcircuit, which is in electrical communication with the thermal sensors50, 52.

Similarly, if only one end of the heating element 16 is exposed to hotwater (e.g., when the shaving razor cartridge is being rinsed in betweenshaving strokes), that end of the heating element will be hotter thanthe other end of the heating element 16. Accordingly, a single sensor ormultiple sensor(s) that take an average temperature will not provide anaccurate reading and may result in power to the heating element beingcut off or reduced prematurely (resulting in the consumer not feeling aheating sensation during shaving). The thermal sensors 50 and 52 mayalso be spaced apart from the heating track 46 to provide a moreaccurate temperature reading. For example, thermal sensors 50 and 52 maybe spaced apart by about 3 mm to about 30 mm depending on the desiredaccuracy and manufacturing costs. In certain embodiments, a protectivecoating may be layered over the electrical circuit track 48 and/or theheating track 46. If desired, the entire second surface may be coveredin a protective coating (e.g., to prevent water ingress which may damagethe sensors 50 and 52, the electrical circuit track 48 and/or theheating track 46).

Referring to FIG. 3, an assembly view of the shaving razor cartridge 12is shown. The housing 18 may define a plurality of openings 54 a, 54 b,54 c and 54 d extending into a top surface 56. In certain embodiments,the top surface 56 may have a recess 58 dimensioned to receive theheating element 16. The plurality of openings 54 a, 54 b, 54 c and 54 dmay extend from the top surface 56 thru the housing 18 to a bottomsurface 60 of the housing 18 (see FIG. 4). The insulating member 40 maybe assembled to the heating element 16 prior to attaching the heatingelement 16 to the housing 18. Each of the legs 38 a, 38 b, 38 c and 38 dmay extend into one of the corresponding openings 54 a, 54 b, 54 c and54 d to align the heating element 16 within the recess 58 and secure theheating element 16 to the housing 18. In certain embodiments, each ofthe legs 38 a, 38 b, 38 c and 38 d may extend thru the bottom surface 60and about a portion of the bottom surface 60 of the housing 18 to securethe heating element 16 to the housing 18 (as shown in FIG. 4). Therecess 58 may define an aperture dimensioned to hold a portion 62 of theflexible circuit 32 supplying power to the heating track 44 and theelectrical track 48. As will be described in greater detail below, theflexible circuit 32 may also carry a signal from the sensors 50 and 52via the electrical circuit to a micro-controller. The housing 18 mayhave a pair of spaced apart recesses 64 and 66 dimensioned to receivethe thermal sensors 50 and 52 (shown in FIG. 2). The spaced apartrecesses 64 and 66 may extend deeper into the housing 18 (i.e., topsurface 56) than the recess 58 to allow the skin contacting surface 30to be generally flush with top surface 56 of the housing 18. The spacedapart recesses 64 and 66 may be positioned within the recess 58.

Referring to FIG. 5, a schematic circuit diagram is illustrated that maybe incorporated into the shaving razor system of FIG. 1 to control thetemperature of the heating element 16 and/or the insulating member 40.FIG. 5 shows one possible example of an electrical circuit 100 thatincludes a temperature control circuit 102 temperature control circuit102 (e.g., a microcontroller) for adjusting power to the insulatingmember 40, thus controlling the temperature of the heating element 16.In certain embodiments, the temperature control circuit 102 (as well asother components of the electrical circuit 100) may be positioned withinthe handle 14. The main function of the control circuit 100 is tocontrol the heating element 16 temperature to a set temperature within areasonable tolerance band by controlling power to the insulating member40. The temperature control circuit 102 may run in cycles of 10microseconds, (e.g. after this period the state of the heater can change(on or off) and during this period the value of the thermal sensors 50and 52 are monitored and processed in the temperature control circuit102).

One or more desired target temperatures may be stored in the temperaturecontrol circuit 102 (i.e., the predetermined value). In certainembodiments, the desired target temperatures may be converted to acorresponding value that is stored in the microcontroller. For example,the microcontroller may store a first temperature value (or acorresponding value) for a “target temperature” and a second temperaturevalue (or a corresponding value) for a “maximum temperature”. Thetemperature control circuit 102 storing and comparing two differentvalues (e.g., one for target temperature and one for maximumtemperature) may provide for a more balanced temperature of the heatingelement and prevent overheating.

The heating element 16 may have different states. One state may be abalanced state (i.e., temperature across the length of the heatingelement 16 is fairly consistent). The balanced state may representnormal or typical shaving conditions (e.g., entire length of heatingelement 16 touches the skin during a shaving stroke so heat isdissipated evenly). The temperature control circuit 102 may calculate anaverage temperature output from the thermal sensors 50 and 52 (i.e., theaverage temperature sensed by the sensors 50 and 52). The temperaturecontrol circuit 102 may compare the average temperature output to afirst predetermined value (e.g., the target temperature) that is storedin the microcontroller. It is understood that the term temperaturevalues may be interpreted as numerical values, which are derived fromelectrical parameters which correlate to the temperature (e.g.,electrical resistance).

The heating element 16 may also have a second state, which may be anunbalanced state where the temperature across the length of the heatingelement 16 is not consistent (e.g., varies by more than 1 C). Thetemperature control circuit 102 may compare individual temperatureoutput values (i.e., an electrical signal related to a temperature ofthe heating element) from each sensor 50 and 52 with a secondpredetermined value (e.g., maximum temperature) that is greater than thefirst predetermined value, which is stored in the temperature controlcircuit 102. Accordingly, the microcontroller may store both the firstpredetermined value (e.g., 48 C) and the second predetermined value(e.g., 50 C).

As previously mentioned, in certain embodiments, the desired targettemperatures may be converted to a corresponding value that is stored bythe temperature control circuit 102. For example, the sensors 50 and 52may generate an output value for a resistance (e.g., R1 and R2,respectively) based on a sensor temperature output (i.e., temperaturesensed by sensors 50 and 52 of the heating element 16). R1 and R2 mayeach be converted to a voltage that is converted to a numerical value ordata that is compared to one or more predetermined values stored in thetemperature control circuit 102. The power from the power source 104 tothe insulating member 40 may be turned off by the temperature controlcircuit 102 sending a signal to an electrical switch 106 to cut offpower to the insulating member 40 by opening or closing the electricalswitch 106 (i.e., open position power is off, closed position power ison). A switch 108 may also be provided, such as a mechanical switch, forthe consumer control (e.g., turn on/off the power to the insulatingmember 40).

In certain embodiments, optimum safety and performance may be deliveredif the microcontroller performs the following functions based on theoutput temperatures of the thermal sensors 50 and 52. If the outputtemperature of one or both thermal sensors 50 and 52 are above or equalto the second predetermined temperature (e.g., maximum temperature) thenpower from the power source 104 to the insulating member 40 is switchedoff (e.g., electrical switch 106 is in open position preventing powerfrom reaching the insulating member 40). If the output temperature ofboth thermal sensors 50 and 52 are above or equal to the firstpredetermined temperature (e.g., target temperature) then the heater isswitched off. If the output temperature of both thermal sensors 50 and52 are below the first predetermined temperature (e.g., targettemperature) then power to the insulating member 40 is switched on(e.g., electrical switch 106 is in close position allowing power to theinsulating member 40). If one of the output temperatures of the thermalsensors 50 and 52 is below and the other one is above or equal to thefirst predetermined temperature (e.g., target temperature), power to theinsulating member 40 is only switched on if the difference between thecolder sensor temperature and first predetermined temperature (e.g.,target temperature) is larger than the difference between the warmersensor temperature and the first predetermined temperature (e.g., targettemperature). In other embodiments, the electrical switch may be opened(power to insulating member 40 turned off) anytime either sensortemperature (50 or 52) is greater than or equal to the secondpredetermined value. In yet other embodiments, the microcontroller maysend a signal to the electrical switch to cut off power to theinsulating member 40 if either the average value is greater than thefirst predetermined value or the individual value sensor temperatures isgreater than the second predetermined. The heating element 16 may neverbe allowed to reach a temperature greater than or equal the secondpredetermined value (e.g., 50 C). In certain embodiments, the firstpredetermined value may be about 46 C to about 50 C (e.g., about 48 Cplus/minus about 2 C) and the second predetermined value may be greaterthan or equal to 50 C to about 60 C (e.g., about 55 C plus/minus about 5C). In certain embodiments, the first predetermined value may be lessthan the second predetermined value by about 2 C or more.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm”.

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A shaving razor system comprising: a handle; ashaving razor cartridge mounted to the handle, the shaving razorcartridge having a housing comprising a guard, a cap, and one or moreblades located between the guard and the cap, said guard beingpositioned in front of said one or more blades, said cap beingpositioned behind said one or more blades, a heating element mounted tothe housing for transferring heat during a shaving stroke, said heatingelement comprising a skin contacting surface and an opposing bottomsurface defined by a perimeter wall; and an insulating member positionedwithin the perimeter wall, the insulating member having a first surfacefacing the bottom surface of the heating element and a second surface.2. The shaving razor system of claim 1 wherein the housing defines atleast one opening extending into the housing.
 3. The shaving razorsystem of claim 2 wherein the perimeter wall has at least one legextending into the at least one opening of the housing securing theheating element to the housing.
 4. The shaving razor system of claim 3wherein the opening extends from a top surface to a bottom surface ofthe housing and the leg extends into the opening and is bent about atleast a portion of the bottom surface of the housing.
 5. The shavingrazor system of claim 1 wherein the insulating member is fixed to theheating element with an adhesive.
 6. The shaving razor system of claim 1wherein the perimeter wall is continuous.
 7. The shaving razor system ofclaim 1 wherein the housing defines a plurality of openings extendinginto the housing.
 8. The shaving razor system of claim 7 wherein theperimeter wall has a plurality of legs extending into the correspondingopenings of the housing securing the heating element to the housing. 9.The shaving razor system of claim 8 wherein the openings extend from atop surface to a bottom surface of the housing and the legs are bentabout at least a portion of the bottom surface of the housing.
 10. Theshaving razor system of claim 1 wherein the second surface of theinsulating member comprises a conductive heating track extending arounda perimeter of the insulating member.
 11. The shaving razor system ofclaim 10 further comprising an electrical circuit track on the secondsurface of the insulating member.
 12. The shaving razor system of claim11 wherein the electrical circuit track is spaced apart from theconductive heating track.
 13. The shaving razor system of claim 11wherein the electrical circuit track extends within the perimeter of theconductive heating track.
 14. The shaving razor system of claim 11further comprising a pair of thermal sensors on opposing sides of theelectrical circuit track.
 15. The shaving razor system of claim 14wherein the thermal sensors are spaced apart from the conductive heatingtrack.
 16. The shaving razor system of claim 11 further comprising aprotective coating covering.
 17. The shaving razor system of claim 1further comprising a flexible circuit and an electrical circuit trackthat is positioned on the second surface of the insulating member,wherein the flexible circuit is configured to carry a signal from atleast one thermal sensor on the electrical track to a micro-controllerpositioned within the handle.
 18. The shaving razor system of claim 17wherein the at least one thermal sensor comprises a pair of thermalsensors.
 19. The shaving razor system of claim 1 wherein the heatingelement comprises steel.
 20. The shaving razor system of claim 1 whereina plurality of legs extend from the perimeter wall.